Vitamin B 12 And Your Diet

Article #4: Vitamin B-12 And Your Diet By Dr. Alan Immerman

If you do not eat animal foods of any kind your fears about dietary deficiency in this highly publicized vitamin will be allayed by this report.

Do we get enough vitamin B12? This is a major concern to people who consume no animal foods (vegans). Much of their worry arises from the wide publicity given to statements like the following which appeared in the prestigious journal, Nutrition Reviews: “Strict vegetarianism in western countries is a form of food faddism which can have serious consequences” due to the possibility of a vitamin B12 deficiency. What are the facts?

First of all, it cannot be said that vegans consume too little vitamin B12 unless it can be shown they have a definite deficiency of this vitamin. Therefore, in order to understand the facts, we must decide how we will determine who is deficient. To be diagnosed as having a dietary deficiency of vitamin B12, all the following five criteria must be fulfilled:

1. Intake of less than the minimum daily requirement of vitamin B12.
2. Abnormally low blood vitamin B12 level.
3. Normal absorption of vitamin B12.
4. Presence of sickness specifically associated with a vitamin B12 deficiency; a specific type of anemia (megaloblastic) and/or nervous system degeneration.
5. Elimination of the signs and symptoms of such sickness following consumption of a small amount of vitamin B12-containing food.

The finding of a vitamin B12-deficient state without fulfillment of every one of these criteria cannot be blamed solely on the diet. This is because all of the following can also cause a vitamin B12 deficiency: stomach disease (interferes with production of intrinsic factor, a chemical necessary for normal absorption of vitamin B12), intestinal disease (may interfere with normal absorption), kidney or liver disease (may increase loss of vitamin B12 from the body), use of alcohol or tobacco, use of some drugs such as neomycin and oral contraceptives and a multitude of other problems. Unless these problems are ruled out by fulfillment of the five criteria, a dietary cause of a vitamin B12 deficiency cannot be diagnosed.

Let’s take a few examples. Say a 58-year-old man on a vegan diet goes to his doctor with signs of nervous system disease. It comes out in the history that this person is a vegan so the doctor presumes that the disease is from dietary vitamin B12 deficiency and prescribes large doses of vitamin B12 supplements. But, without investigation of this person’s ability to absorb vitamin B12, his disease cannot be said to come from dietary deficiency alone. He could have pernicious anemia—deficiency of the intrinsic factor needed for absorption.

Or consider the vegan who has routine blood analysis done and it is found that his vitamin B12 level is low compared to the standard American range. The doctor would probably warn this individual of the grave consequences of continuing on his diet, even though this person feels fine. This individual cannot be classified as vitamin B12-deficient, however, because he has no symptoms of the diseases associated with a vitamin B12 deficiency.

As a third example, let’s consider the most complex case: a vegan with a vitamin B12 deficiency-associated illness, normal absorption as reflected by use of routine absorption testing (the Schilling test) and disappearance of symptoms after ingestion of vitamin B12 supplements of routine dosage. Wouldn’t this be a clear case of dietary vitamin B12 deficiency? Not necessarily—it could be a case of poor absorption not revealed by routine testing. A case like this occurred where the fault in absorption was not detected until sophisticated methods were used.

Short of sophisticated testing available only in research centers, the only way this fault in absorption, and probably many other similar faults, would be discovered is by experimental oral administration of small amounts of vitamin B12, as opposed to the large amounts routinely used. For this reason, fulfillment Of criterion No. 5 (positive response to consumption of small amounts of vitamin B12) is essential for a diagnosis of dietary B12 deficiency.

As simple and full of common sense as are these five criteria, we see many cases in the medical literature in which one or more of them have not been fulfilled. For example, Smith in 1962 investigated twelve vegans and found vitamin B12-associated illness in three of them.

He did not, however, check to see if they were able to absorb vitamin B12 efficiently; thus his diagnosis of dietary vitamin B12 deficiency is unconvincing. There are even cases presented as dietary vitamin B12 deficiency in which no accurate diet history is reported to show that no vitamin B12-containing foods have been eaten.

Verjaal, et al., in 1967, presented the case of a vegan with nervous system disease which the researcher attributed to the diet without checking absorption or the response to small amounts of oral vitamin B12. Connor, et al., in 1963, discussed two cases in which he also failed to investigate absorption.

In preparing this article, I have reviewed every article discussing cases of reported dietary vitamin B12 deficiency, and I can say that lack of fulfillment of all five criteria, as in the articles just described, is the rule, not the exception.

On the other hand, many studies have reported vegans with normal vitamin B12 status and complete health. Hardinge, et al., in 1954, studied 26 vegans and found them to be healthy. Ellis, et al., in 1970, studied 26 vegans and found the same.

Roberts, et al., in 1973, investigated 322 Indian vegans during pregnancy. All but one were perfectly healthy and this one was not studied to determine whether she could normally absorb vitamin B12. Sanders, et al., in 1978, studied 34 vegans and found no sickness.

The conclusion must be that the vast majority of the studies which have reported abnormal vitamin B12 status in vegans have not been thorough enough to prove the problem was from the diet only, and that, on the the other hand, many studies have found normal vitamin B12 status in vegans. Though this is hard for a western nutritionist to accept, no Indian doctor would have the slightest problem with it.

Indians, for the most part, are not pure vegans, as they consume small amounts of dairy foods. These amounts, however, fall far below the amounts that would be needed to supply adequate amounts of vitamin B12 if western dogma is valid.

Yet, in India, vegetarians have lived for ages and have begotten and reared healthy children who, in turn, have never eaten fish, fowl or meat. There is no evidence to suggest that such a vegetarian population consuming adequate lactovegetarian food is any way different from the non-vegetarians.

As Dr. David Reuben points out, the news that an almost-vegan diet is dangerous “will come as a surprise to 500,000,000 Hindus, most of whom don’t eat any meat or animal products at all from the moment they are born until the moment they die (with the exception of mother’s milk for a while). The Hindu religion has been around for over 10,000 years, or about 98 centuries longer than modern American medicine.

But how do vegans get their vitamin B12? Since it is produced only by bacteria, and vegans don’t eat the animals that had the bacteria growing in their second stomach (rumen), what is the source of this vitamin B12?

There are no definite answers to this question, but the fact that most vegans are healthy shows one of the following answers must be applicable: Absorption of the vitamin B12 routinely produced by bacteria living in the intestine (supposedly they live in a area where the vitamin cannot be absorbed, but an adaptation may occur in vegans); no loss of vitamin B12 from the body, thus no need for additional dietary vitamin B12; ingestion of vitamin B12 in water (from the well or the distiller) due to bacterial contamination; accidental ingestion of insects or bacteria containing vitamin B12; presence of vitamin B12 in root vegetables due to absorption of vitamin B12 from the soil where it was produced by bacteria; presence of vitamin B12 in soil on poorly washed root vegetables; presence of vitamin B12 in seaweed (all but green) and/or contamination of plant foods with vitamin B12 produced by bacteria.

It is true that vitamin B12 is produced only by bacteria, but these bacteria are almost everywhere, and for this reason vitamin B12 has been found in some samples of many vegetables.

A vegan diet, therefore, does not have “serious consequences” as threatened by Nutrition Reviews; it is quite the reverse, as contrariwise it has such “beneficial consequences” as vegans not having to fear any risk of ever suffering cardiovascular disorders or colon and breast cancer. The low fat intake of vegans minimizes the chance of these diseases. The threat of a vitamin B12 deficiency is more often than not hypothetical rather than actual.

It is important to emphasize that deficiency may be present only if a person has low blood vitamin B12 levels plus illness associated with vitamin B12 deficiency. Indications of a low vitamin B12 level by itself will not interfere with attaining a long and healthy life with full capacity for normal reproduction. The contrary has never been proven to be so, unless the deficiency is accompanied by illness as discussed above.